Calcium Homeostasis

Question 1

Processes that need calcium

Answer 1

Neuromuscular excitation, blood coagulation, hormone secretion, enzyme activity, fertilization

Question 2

How calcium is stored in the bones

Answer 2

Hydroxyapatite

Question 3

Major sites of regulation of calcium

Answer 3

Bone, muscular, kidney, gut

Question 4

Parathyroid hormone

Answer 4

Increases serum calcium mainly by increasing osteoclast activity, secretion is determined by calcium concentration

Question 5

Chief cells

Answer 5

Cells in parathyroid that produce PTH

Question 6

Oxyphils

Answer 6

Cells in parathyroid with an unknown function

Question 7

Calcium sensitive receptors

Answer 7

Found in parathyroid gland, renal tubules, C cells

Question 8

PTH secretion pattern

Answer 8

Continuous, is not stored

Question 9

Effect of vitamin D on PTH

Answer 9

Decreases its secretion

Question 10

Calcitonin

Answer 10

Produced by thyroid C cells, secreted in response to hypercalcemia, inhibited by vitamin D

Question 11

Effect of calcitonin

Answer 11

Lowers serum calcium by inhibiting osteoclasts , reduces reabsorption in nephron

Question 12

Calciferols (vitamin D)

Answer 12

Enhance absorbance of calcium in gut and reabsorption by nephron, PTH and calcitonin increase its synthesis

Question 13

Effect of GH / IGF1 and thyroid hormones on calcium

Answer 13

Increase bone mineralization and growth

Question 14

Effect of estrogens and androgens on calcium

Answer 14

Oppose PTH by slowing turnover of bone

Question 15

Effect if glucocorticoid on calcium

Answer 15

Oppose calciferol actions in GI tract

Question 16

Hyperparathyroidism

Answer 16

Hyoercalcemia, fractures, mineralization of soft tissues, thirst and urination because calcium blocks ADH

Question 17

Hypoparathyroidism

Answer 17

Hypocalcemia, muscular weakness and ataxia, cardiac arrhythmia

Question 18

Causes of hyperparathyroidism

Answer 18

Primary (hyperplasia, adenoma, genetic) or secondary (kidney failure, vitamin D deficiency)

Question 19

Causes of hypoparathyroidism

Answer 19

Surgery and injury to neck, autoimmune disease, Di-George syndrome, low magnesium

Question 20

Hyoerparathyroidism treatment

Answer 20

Surgery, radiation therapy, bisphosphonates, balanced diet, treat chronic kidney failure

Question 21

Hypoparathyroidism treatment

Answer 21

High calcium and vitamins D supplements, IV drip if necessary

Question 22

Hypercalcitonism

Answer 22

Weaker symptoms of Hypoparathyroidism

Question 23

Rickets symptoms

Answer 23

Bone malformations, weakened and large joints, costochondral swelling, soft skull

Question 24

Milk fever

Answer 24

In dairy cows during periparturient period

Question 25

Eclampsia

Answer 25

Dogs with large litters so you have high lactation and not enough calcium for the mother